Jack Kelly’s closing speed is impressive. Quarterbacks who think they have an extra second or running backs who are certain they can get around the edge are often left disappointed and a little surprised. “How fast is that guy?” they wonder.

BYU’s Jack Kelly was chatting with reporters after a practice at Trinity University in San Antonio and two days before the Cougars’ 36-14 Alamo Bowl victory over Colorado when fellow linebacker Harrison Taggart stood behind the cameras and playfully ...